Sewing machine



J. H. PIKUL SEWING MACHINE Jan. 16, 1.940.

Filed Dec. 1, 1958 2 Sheets-Sheet 1 lNVElNFUFL Jam 16, 1940.

y.1. H. PIKUL 1 2,187,248

SEWING MACHINE Y Filed Dec. 1, 1938 2 Sheets-Sheet 2 Patented Jan. 16, 1940 UNITED STATES PATENT OFFICE invention relates to sewing machines of the type designed:l to sewaf suitablyl positioned lineof "stitches around an area or opening',`such Y `asV a buttonhole or aneyelet, in the work, and more particularlyto the work holding and clamping mechanism employed in suchfmachines.

`In buttonhole and similar machines asheretofore `usually constructed, the work clamping mechanism comprises a two-part worker clamp plate the sections of which are positioned at opposite sidesof the buttonhole slit or other open- `ing in the work and cooperate respectively with `a pair of spacedclamping feet between which and said plate sections the work is clamped. In

1,6 such machines it is customary, after clamping `the worh, to spread the clamps, i. e., to move the plate sections and their respective cooperating clamping feet slightly away from one another to stretch or tension the fabricin a direction transversevto the length of the buttonhole. The use of spaced workplate sections and spaced clamping feetleavesthe work unclainped at the ends of the stitching area, i. e., the region in which the stitches are positioned, with the result that there is a tendencyto distort thework, the stitches, although uniformly spaced by theneedle, being im` properly positioned in the work when the tension isreleased. Moreover,` tensioning ofthe" fabric in one direction onlyis particularly unsuitable to the formationof circular eyelets or the like. The present invention has for an object tosimplify the machine by eliminating the spreadingof the work clamp and the mechanism `for performing this function, and to provide an improved work clamping mechanism, comprising a unitary work plate and a cooperating unitary `clamping member; whereby the fabric will be tightly;` and securely held at substantially all points surrounding the stitching area, and will 40` be suitablystretched or tensioned in all direcL tions as an incident to the clamping operation itself.

` Machines of the type under consideration alsol include cutting "mechanism, comprising a pair of mechanism having athroat plate likewise located below the work, said cutting and stitching mechanisms, on the one hand, and theywork plate or clamp, on the other,` being relatively movable in directions parallel to the work plate to bring the "cutting elements and the throat plate alternately into `position tooperate Aupon the work at the pointwheretne buttormoie jor the' like ist@ be* ness of the latter.

cooperating cutting elements located respectively above and below the work, as well as stitching top surface oftheworkplate, its bottom surface is necessarilyspaced from the bottom surface of said plate a distance corresponding to the thick- Consequently, the work plate must have elongated openings therethrough "in which the throat plate and lower cutting element can move into land out of, operative position, or saidV throat plate andcuttingelement must ybe `given movementstransverse `to the work plate in addition to their relative movements parallel thereto: otherwise they, when in operative position, will be spaced too far from the work for accurate and satisfactory operation unless the work plateis made undulythin. The present in.

Vention has for another object the provision of'a construction employing a work plate of adequate thickness and, except in the region of the stitching area, of substantially unbroken continuity as to its work supporting surface,` wherein the throat plateand lower cutting element arelzat all times beneath the work plateand move relativelyto the latter only in planes parallel theren to, but wherein the bottom surface of the work l is positioned substantially flush with said cutting element and throat plate when said parts arelin operative position withsrespect thereto.

` The foregoing and other objects of. the inven` ti0n,"togetlier with means whereby the latter may be carried into effect, will best be understood from the following description of an illustrative embodimentthereoi shown inthe accompanying drawings, this," however, having been chosen for purposes of exemplication merely, as it will be obvious to` those skilled in the art `that the invention, as denedby the claim hereunto ap-v pended, may be `otherwise `embodied without de- `parting from its spirit and scope.

In saiddrawings: l

Fig. `1 is `a side elevation, partly in section, of a machine including `work clamping mechanism embodying the invention.

Fig. 2 is a plan view, partly broken away, of

thework clamping mechanism per se and asso- "ciated parts.

Fig. 3 is a section taken substantially on Athe line 3-'3, Fig. 2, showing the parts in a different W position.

Figs. 4 and 5 are views similar to Fig. 3 showingthe parts in different positions.

Fig. 6 is a` `section taken substantially on ,the linee- 6, Fig. 5.

Referring to Fig.` l, the invention is shown as applied to a buttonhole or similar machine of a wellfk'nown type `comprising "a stationary bed `--fifrar`n`e l5? carrying the-work clampingumechanism, hereinafter described, and a movable Stitch frame or head I6 carrying the stitching mechanism as well as cutting mechanism for cutting the buttonhole or the like. The stitch frame I6 is movable longitudinally over the bed frame I to' bring the stitching and cutting mechanisms alternatively into operative relationship with the work, and also both longitudinally and laterally to position the stitches in accordance with the work to be performed, by means of mechanism operated by a main cam I'I carried by the stitch frame I6 and rotated by a feed shaft I8 likewise carried by said frame. This mechanism is well known in the art, being shown, for example, by the patents to Reece, No. 240,546,.April 26, 1881, and No. 655,637, August 7, 190,0, and many others, and requires no detailed description herein.

The stitching mechanism comprises a needle I9 carried by a needle bar 20, and looper mechanism I4 which may be substantially as shown in the patent to Grip, No. 1,905,854, April 25, 1933, said needle bar and looper mechanism being carried respectively by upper and lower turrets 2| and 22 rotated in unison at the proper time by gear segments 23 and 24 carried by a rock shaft 25 operated by the main cam I1 as further described in the Reece patents above referred to. The lower turret 22 also carries a throat plate 26 through which the needle I9 passes to cooperate with the looper mechanism. The needle bar 20 is reciprocated vertically and vibrated laterally in its turret 2| by means of suitable cams on a stitching shaft 2l through mechanisms generally indicated at 28 and 28a, respectively, and which may be substantially as shown and described in the patent to Reece No. 1,991,627, February 19, 1935. The looper mechanism carried by the turret 22 is likewise operated from the stitching shaft 2'I by mechanism generally indicated at 29 and which may be substantially as shown and described in the patent to Grip above referred to and in thepatent to Dunnell No. 1,935,083, November 14, 1933.

The cutting mechanism comprises upper and lower cooperating cutting elements 30 and 3 I, the former of whichis carried by a lever or arm 32 operated at the proper time from the main cam I'I, as described more fully in the patent to Kiewicz, No. 1,841,133, January 12, 1932. l

The work clamping mechanism, hereinafter more fully described, and which, as above stated, is carried by thebed frame I5, includes a work or clamp plate 33 and cooperating clamping means carried by a pair of arms 34 pivoted at 35 to said work plate and operated by mechanism including a swinging frame or rocker 36, toggle 3'I and lever 38 which in turn is operated by the cam I'I, the latter mechanism, as herein shown, being substantially as more. fully described in the Kiewicz patent above referred to and in the patent to Hill, No. 713,764, November 18, 1902.

It will be understood that, in machines of this character, suitable mechanism is provided whereby the machine, when started, Will perform its operative cycle and then automatically stop, said cycle including, rst, a closing of the work clamp to clamp the work, then a movement of the stitch frame from the cutting position shown in Figs. 1, 3 and 5, in which the cutting elements are adjacent the stitching area, into a stitching position in Which the stitching instrumentalities are adjacent said area, a stiching operation of a character determined by the design of the feed mechtion, and, finally, the opening of the work clamp to release the work, said cycle also including a cutting operation which may be performed either before or after the stitching operation according to the design or adjustment of the machine.

Except as hereinafter pointed out, or as they enter into combination with parts hereinafter described, the mechanisms above referred to specically form no part of the present invention and may be as shown and described in the patents referred to, or otherwise, as will be well understood by those skilled in the art.

In accordance with the present invention, the work plate 33 comprises a single unitary member (i. e., it is not divided into relatively movable sections) removably positioned on the bed frame I5 by lugs or dowels 39 projecting upwardly from the latter and received in openings 40 in said work plate. Adjustably secured, as by screws 4I, to the rear or inner end of the work plate are lugs 42 to which the arms 34 are pivoted, said plate having slots 43 through which the lower ends of said arms project for detachable engagement with the rocker 35, permitting removal of said arms with the work plate. At its underside, the work plate 33 is grooved, as shown at 44, to receive the throat plate 26 and lower cutting element y3| and permit movement of sai-d plate and element alternatively into operative position, the portion of said plate above said groove being, however, of substantial thickness, and its bottom surface being substantially flush with the tops of said plate and element, except for the necessary clearance which is somewhat exaggerated in Figs. 3 and 5.

The portion of the work plate 33 last referred to is provided with an opening 45 therethrough, said opening being preferably, and for convenience, formed in a removable portion or slide 46 which, however, is normally stationary with respect to the plate so as to constitute a unitary part thereof, being secured in this position by a spring pressed latch 46a as shown in Fig. 2. The open'- ing 45 is formed with downwardly converging, preferably serrated edges, and cooperating therewith is a unitary clamping member 4l of substantially complementary form, pivoted at 48 to the arms 34 and extending between them, said member having therethrough an opening 49 which, when said member is in clamping position, is alined with the opening 45 and with the cutting element 3l when the latter is in operative position as shown in Figs. 3 and 5. "7

The opening 49 is of a suitable size and shape to enclose lthe stitching area and, therefore, to receive all of the stitches positioned by the feeding movements of the stitch head and the rotation of the turrets in accordance withthe charaoter of the work to be performed. The particular machine herein shown is arranged to sew circular eyelets, and the opening 49 is accordingly of circular shape. To the same end, the lower cutting element SI comprises a round punch to cooperate with a cutting block or anvil 30 carried by the lever 32, said punch having a shank received in a socket 53 carried by the stitch frame I6 and secured therein by a set screw 5I, a series of interchangeable punches of different sizes'being preferably provided, said punches, however, all having Shanks of a size to fit the socket 59, so as to be automatically centered merely by insertion into said socket. It will, of course, be understood that for sewing buttonholes or the like of shapes other than circular, work plates and clamping members having openings 45 and 49 of appropriate shapes can be substituted for those shown and that the punch 3I can be replaced 'by cutters likewise of suitable form' in accordance with the usual practice.`

The opposed coacting edges of the opening 155` and clamping member `ll'l are continuous except for narrow registering thread vchannels 52 and 53 to accommodate the needley thread when the parts are moved from stitching to cutting position. Consequently, it will be seen that saidv the pivotal mounting 48 of said member permit-` ting the latter to engage the work evenlyysaid member being thereafter furtherdepressed' into the position shown in Fig. 5 to clamp the `work i at the edge of the opening 45` between its peripheral surface and said edge,k ultimately displacing or depressing said work into said opening into a position with its bottom surface subi stantially flush with the bottom surface of the work plate and, therefore, with the tops of the throat plate 26 and cutting element 3l. quently, the movements of thevthroat plate and cutting element into and out of operative position, i. e., into and out of register with the opening 45,-need be only in a plane parallelwith the work plate, said members, however, being in close vproximity tothe work when Ibrought into operan tive position, The nal downward movement of i the clampinglmember after the work W has been l grippedbetween it andthe edgel of the opening y in the work plate acts to stretch said work across the opening 49 like a drum head, thereby tensioning the same substantially equally in all directions, this action being incidental to the clamping operation itself and without any spreading of theclamp.

`I claim:

In a sewing machine, the combination with a i work plate having therethrough an opening with downwardly converging serrated edges, of a Work clamping member having an exterior form substantially complementary to said opening.

` JOSEPH H. PIKUL.

Conse- 

